Uncertainty evaluation in laser differential confocal radius-of-curvature measurement

Radius of curvature is one of the primary parameters of optical elements, and radius-of -curvature measurement is critical for precision optics manufacturing. A laser differential confocal radius-of-curvature measurement system was constructed and uncertainties of two groups of curvature radius measurement results were evaluated. It is demonstrated that the measurement results of two groups of curvature radius have a difference of 0.001 15% with each other, which are all consistent with the nominal value, moreover the uncertainties of two groups are both superior to 3.211 1110-4 mm.